Antimicrobial finishing of regular and modified polyethylene terephthalate fabrics

An effective two-stage method has been developed for imparting antimicrobial properties to regular polyethylene terephthalate (R-PET), polyethylene glycol modified polyethylene terephthalate (PEG-M-PET), R-PET/Cotton blend (R-PET/C) and PEG-M-PET/Cotton blend (PEG-M-PET/C) fabrics. The method consists of partial hydrolysis of the fabrics to create carboxylic groups in PET macromolecules followed by subsequent reaction with dimethylalkylbenzyl ammonium chloride (DMABAC) under alkaline conditions. The reaction conditions such as pH, reaction temperature and time, carboxylic content, and DMABAC concentration were studied. Characterization of the finished fabrics was carried out through scanning electron microscopy (SEM) and Fourier transform infrared spectra (FTIR). All the modified PET fabrics showed excellent antibacterial activity towards Gram-positive (Bacillus mycoides), Gram-negative (Escherichia coli), and nonfilamentous fungus (Candida albicans). The achieved antimicrobial functions on the PET fabrics are durable in repeated laundering processes. Even after laundering 10 times the fabrics could still provide more than 85% of its antimicrobial activity against B. mycoides, E. coli, and C. albicans. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

钛酸酯催化环氧树脂固化动力学研究

用FTIR“原位”技术,研究了钛酸酯(Tc-114)偶联剂对环氧E-44和二氨基二苯基甲烷(DDM)固化反应的催化作用,得出固化程度与时间的关系曲线。又根据DSC曲线,分别算出加有Tc-114和不加Tc-114的两个固化体系的反应表观活化能和反应级数。结果表明,Tc-114的存在使环氧固化反应活化能降低,催化作用明显。     

UV-固化光纤色标油墨

报导了一类新型的化学功能材料———ＵＶ固化光纤色标油墨。该材料由可ＵＶ固化的有机硅环氧安息香酸丙烯酸酯（ＳＥＢＡ）和脂环族环氧丙烯酸酯（ＡＣＥＡ）两种光敏预聚物为基料，以自行合成的光敏染料———分散红氨基甲酸酯丙烯酸酯（ＲＵＡ）、分散蓝氨基甲酸酯丙烯酸酯（ＢＵＡ）和吖啶黄氨基甲酸酯丙烯酸酯（ＹＵＡ）为着色剂，加入必要的添加剂配制而成的ＵＶ固化光纤色标油墨。该色标油墨已在光纤生产中得到应用。     

改性己二胺制备TG301环氧树脂室温固化剂

已二胺经与环氧树脂进行羟烷基化及与丙烯腈进行氰乙基化反应达到改善低熔点低毒性．低脆性的综合效果．文中介绍了改性乙二胶固化剂的制备方法，质量指标和有关固化特性等．     

Investigation into the morphological and mechanical properties of date palm fiber-reinforced epoxy structural composites

This study aims to examine the morphology and mechanical properties (tensile, flexural, and compressive) of epoxy composites reinforced with epoxy date palm leaves (EDPL), epoxy date palm branch (EDPB), and epoxy/hardener date palm core shell (EDPC) fibers (particle size <1 μm depend on the date palm fibers). A three-step technique was used to obtain the composites. The EDPL composites showed a maximum tensile strength of 3.45 MPa, while the EDPB composites showed maximum compressive and flexural rigidity of 9.46 and 5.55 MPa, respectively, owing to the good compatibility of fiber-matrix bonding. In this work, epoxy composites reinforced with date palm fibers (DPF) leaves, branches, and core shell were recycled using a cost-effective and easily reproducible three-step technique. EDPC fibers fabricated with 64.65% weight carbon fibers content demonstrated improved tensile strengths and stiffness properties. The three samples of palm date composites revealed mechanical properties that could be used to trial these fibers for manufacturing purposes, and to exploit their extraordinary mechanical properties shown in current results.     

Synergistic effects of organically modified montmorillonite in combination with metal oxides on the fire safety enhancement of intumescent flame-retarded epoxy resins

Synergistic effects of organically modified montmorillonite (OMMT) in combination with different metal oxides (Bi₂O₃, Sb₂O₃, and MoO₃) on the fire safety enhancement of the intumescent flame-retarded epoxy resins (EPs) were systematically evaluated. The results from X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses show that the OMMT and metal oxides acquire a uniform distribution in the EP matrix, and OMMT platelets exhibit a fully exfoliated state. The flammability and thermogravimetry (TG) tests show that the intumescent flame retardant (IFR)-OMMT-metal oxide ternary system can endow EPs with the higher synergistic efficiencies on the enhancement of flame retardancy, smoke suppression properties, and charring ability compared to those of IFR or IFR-OMMT system, and the synergistic efficiency is the following order: IFR/OMMT/Sb₂O₃ > IFR/OMMT/MoO₃ > IFR/OMMT/Bi₂O₃. In particular, the sample, filled with 1.5 wt% OMMT, 1.5 wt% Sb₂O₃, and 27 wt% IFR, passes the UL94 V-0 rating and acquires the highest limiting oxygen index value of 28.5% among the samples. The IFR-OMMT-metal oxide ternary system exerts a better synergistic effect on the generation of crosslinking and aromatic structures that supply the excellent charring effect and barrier effect for the EPs, and the synergistic efficiency of IFR-OMMT-metal oxide ternary system is varied with the types of metal oxides.     

Zirconium-Embedded Polyhedral Oligomeric Silsesquioxane Containing Phosphaphenanthrene-Substituent Group Used as Flame Retardants for Epoxy Resin Composites

A zirconium hybrid polyhedral oligomeric silsesquioxane derivative (Zr–POSS–bisDOPO) is synthesized by the corner-capping and Kabachnik–Fields reactions. It is characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR), and then used as a flame retardant in diglycidyl ether of bisphenol A (DGEBA) to endow epoxy resin (EP) with flame retardancy. The flame retardancy, thermal stability, and mechanical properties of the cured EP/Zr–POSS–bisDOPO composites are investigated. The results show that when Zr–POSS–bisDOPO is added by 5–7 wt%, the EP/Zr–POSS–bisDOPO composites pass the UL-94 V-0 rating test. In addition, they have a better flame-retardant effect than pure EP. The combination of Zr atom embedded in the Si O cubic cage and the two phosphaphenanthrene substituent groups in one corner of cubic cage is expected to realize the Zr/Si/P ternary intramolecular hybrid synergistic effect and achieve the possibility of dispersing metal–POSS cages at a sub-micrometer-scale level into polymer matrix. It also proves that Zr–POSS–bisDOPO produces phosphorus-containing free radicals and terminates the chain reactions in gas phase. Meanwhile the Si O Si and Zr O units are retained in the solid phase, which promote the char formation and enhance the flame retardancy. This kind of Zr-doped POSS will be helpful for developing the new metal–POSS hybrid flame-retardant and polymer composites.     

Bioderived Bilayer Shell Modification β-FeOOH Nanorods via Self-Assembly Technique as Sustainable Flame Retardants for Enhancing Flame Retardancy of Epoxy Resin

The design and application of bioderived flame retardants have been widely conducted to meet the concept of green and sustainable development. Here, self-assembly technique is used to prepare core–shell bioderived additives by using β-FeOOH as the core and polydopamine (PDA)/tannic acid (TA) bilayer as the shell, following adsorption of nickel ions to enhance the thermal stability, flame retardancy, and mechanical properties of epoxy resin (EP). The molecular structure of biobased resources is rich in hydroxyl groups and carbon content, which can be dehydrated and carbonized during combustion and promote the formation of robust protective char layer. With the addition of 5 wt% β-FeOOH@PTNi, the EP composites can pass V-0 rating in the UL-94 test. The peak heat release rate and total heat release decrease by 28.4% and 17.4% compared with pure EP. The bioderived nanorods can capture the oxygen free radicals, contributing to flame retarding in gaseous phase. Thus, the release of high-toxic CO and flammable gaseous is significantly suppressed. Besides, the storage modulus of EP composites increases by 16.0% with the addition of 5% β-FeOOH@PTNi compared with pure EP. This work provides a sustainable methodology for the design of bioderived flame retardants for EP.     

Effect of Bio-Based Cobalt Alginate on the Fire Safety and Mechanical Properties for Epoxy Resin

There is a growing demand to develop epoxy resins (EP) with smoke suppression as well as satisfactory flame retardancy. Herein, bio-based cobalt alginate is successfully fabricated and incorporated into EP to prepare EP/Cobalt Alginate composites with better fire safety performance. The addition of cobalt alginate reduces the thermal-decomposition rate, temperature at maximum weight-loss rate of EP, whereas obviously improves the thermal stabilities at a higher temperature range. Furthermore, the addition of cobalt alginate substantially reduces the fire hazard of EP, resulting in 56.2% reduction in peak heat release rate, as well as 17.8% and 56.3% reduction in total smoke production and peak smoke production rate, respectively, compared with EP matrix. Moreover, the presence of cobalt alginate increases smoke-suppressant properties, according to the smoke density test. Additionally, the incorporation of cobalt alginate has no obviously destructive effect on the mechanical properties of EP, while EP/Cobalt Alginate-3 exhibits a 27.0% improvement in impact strength. In prospective, this study may provide a significant method for producing eco-friendly flame retardant EP.     

Intraspecific variation and interspecific differences in sex pheromones of sibling species inCtenopseustis obliquana complex

The specific status ofCtenopseustis obliquana pheromone-types I, II, and III has been more fully examined. Females of types I and III produce a mixture of (Z)-8- and (Z)-5-tetradecenyl acetates (Z8-14:Ac, Z5-14: Ac). The previously reported different ratios of these two components in females of the two types (type I=8020, III=9010) have been reinvestigated. The median ratios of each type differed significantly, although there was some overlap in the ranges of these ratios. A field cage trial showed that males of type III are attracted to females of type I, so the observed differences may be ascribed to intraspecific variation. In contrast to females of types I or III, females of type II produce Z5-14Ac but no Z8-14Ac. The electroantennogram (EAG) profile of antennae of type II males shows a maximum response to Z5-14Ac, while the EAG profiles of types I and III show a strong response to Z8-14Ac. In wind tunnel tests using mixtures of these two compounds, type II males prefer blends consisting of all or mostly Z5-14: Ac, while type I males showed a preference to a mix of 70% Z8-14Ac plus 30% Z5-14Ac. We found that type I males are attracted to type I females when offered a choice between type I and type II females in a field cage test and that type II males similarly prefer type II females. Males of types I and II have specialist cells for Z8-14Ac and Z5-14Ac but differ with respect to relative densities of these cells and to further cell types responsive to other alkenyl acetates. Type IIC. obliquana is considered therefore a sibling species of types I and III. In addition, the amount of Z5-14Ac produced by type II females varied geographically. Females from the North Island produced significantly less (median=1.2 ng) Z5-14Ac than females from the South Island (median=2.2 ng). Type II populations in the North Island morphologically resembled sympatric type I, rather than type II from the South Island and are designated as type II (North Island). Type II (North Island) populations have so far been found only at Rukuhia (near Hamilton) and from Kerikeri. In contrast, type II populations are sympatric with type III populations over much of the South Island. In a field cage trial, males of types II and II (North Island) were attracted to females of both II and II (North Island). We tentatively ascribe the differences between type II and type II (North Island) to intraspecific variation.